Display screen or portion thereof with an animated graphical user interface



FIG. 1 is a front view of a display screen or portion thereof with an animated graphical user interface showing a first image in a sequence according to our new design;

FIG. 2 is a second image thereof;

FIG. 3 is a third image thereof; and,

FIG. 4 is a fourth image thereof.

The appearance of the display screen or portion thereof with an animated graphical user interface sequentially transitions between the images shown in FIGS. 1-4. The process or period in which one image transitions to another forms no part of the claimed design.

The outermost broken-line rectangle illustrates the perimeter of a display screen or portion thereof. The remaining broken lines illustrate portions of a graphical user interface. The broken lines form no part of the claimed design. 

CLAIM The ornamental design for a display screen or portion thereof with an animated graphical user interface, as shown and described. 